Epicor Software Dot Net Developer-c# interview questions

Online test -MCQ easy, program to find min & max array element, program to generate largest number using all elements of array & check if string is balance (count of all distinct charters should be same) Technical Round - abstraction,interface, why abstraction when we can do all the same functionalities with normal class, dispose vs finalize , what does happen at machine level when we use dispose, ienumerator vs ienumerable , how does c# code executes in dot net, ref vs out, value type vs reference type, method calling in case of inheritance with multiple interfaces, implicit vs explicit, garbage collector................. interview tested all round knowledge of c# and i was rejected after this round.....2 yrs exp